What I learnt about food fermentation from Sandor Katz


I was brought up in Ukraine where fermenting foods is a regular ritual in every home. People pickle and ferment foods for preservation as it’s often difficult to get certain fruits and vegetables out of season and also to make sure that the abundance of those foods in season isn’t wasted. But I wonder if my grand parents and their grand parents knew how many health benefits these fermented foods had?

Personally, I ate and drank lots of fermented foods growing up – sauerkraut, kefir, kvas – but I didn’t know about the wonderful effects of good bacteria on my wellbeing until much later in life. Sure, I always heard that yoghurt was good for me but I used to eat the sugary, low-fat crap until a few years ago. What I am talking about is a much larger spectrum of microbial cultures that we need for optimal health and that we should ideally be getting from a VARIETY of fermented foods. So where am I going with this?

Could have been my grandmother. Pic from http://foodieukraine.com/cucumbers/

Could have been my grandmother. Pic from http://foodieukraine.com/cucumbers/

I recently attended a full day’s fermentation workshop with Sandor Ellix Katz, who is well known for his books Wild Fermentation and The Art Of Fermentation. He is the master of the craft and advocates eating live fermented foods for optimal health.

“Wild foods, microbial cultures included, possess a great, unmediated life force, which can help us adapt to shifting conditions and lower our susceptibility to disease. These microorganisms are everywhere, and the techniques for fermenting with them are simple and flexible.” – Sandor Katz

In his teachings on DIY fermentation, Katz encourages us to try the low-tech, simple techniques and methods at home and to eat a variety of live fermented foods (sauerkraut, kimchi, kefir, yoghurt, aged cheeses, miso, kvas, kombucha, salami and the list goes on) to promote diversity among microbial cultures in our bodies. He claims that it is that biodiversity that is increasingly recognised as critical in maintaining our wellbeing and helping to prevent disease.


Here is a list of insights into fermented foods I picked up from the workshop: 

  • First of all, fermented foods are foods that have gone through a process of lacto-fermentation in which natural bacteria feed on the sugar and starch in the food creating lactic acid. That’s what gives fermented foods that lightly sour, tangy taste and softness.
  • Fermenting foods makes them better for us. Fermenting is a form of pre-digesting, making foods more digestible and nutrients more bioavailable. For example, fermenting dairy breaks down the lactose making it easier to handle for those people usually sensitive to lactose in dairy. That’s why someone with hard time drinking milk, can easily consume yoghurt and aged cheese. Gluten is also broken down during fermentation, and although it’s not removed from the food completely, it is reduced making things like sourdough bread and fermented grains easier to digest.
  • Fermentation also liberates minerals and studies have shown that fermented foods are higher in minerals than their non-fermented sources. Please pass the cheese and kefir!
  • Soaking and fermenting or partially fermenting grains and legumes will significantly reduce some present antinutrients such as phytic acid, which can bind to minerals in that food preventing their absorption; oxalic acid present in some wild foods like sorrel and almonds and that can also limit some nutrient absorption if consumed in large doses is also broken down; cyanide compound (yep the poison) in cassava is removed through soaking and cooking.
  • According to Sandor, German scientists have found that pesticide residue diminishes with fermentation. Pretty cool!
  • Fermented foods have also been found to have an elevation in already present B vitamins. Who needs Berocca!?!
  • Sauerkraut contains high levels of glucosinolates. These compounds have been shown to have anti-cancer activity in laboratory research.
  • Foods such as natto are high in vitamin K2 and fibrin, which reduces fibrosis, that constricts circulation. However, caution should be taken by those with blood clotting disorders.
  • The main benefit of fermented foods is of course the presence of live bacteria, which we need for healthy gut flora. Our gut health has a direct impact on our immune system, and fermented foods help to keep up our immune defence, while also assisting digestion, mental health and so much more.
  • Having yoghurt a few times a week or a probitic capsule is good but it’s not going to provide you with the diversity of macrobiotic communities you need for optimal gut health and wellbeing. Biodiversity is the name of the game and we need a variety of fermented foods, at different stages of fermentation, to get all the different strains of cultures into our system.
  • You don’t need fancy fermenting vessels, crocks and starter cultures to start fermenting. If you have vegetables, leftover jars with lid and salt, you can start fermenting right now.
  • Almost any food can be fermented but some lend themselves better to the process than others (e.g plant based foods).
  • Certain foods will require a fermentation starter but most already contain components that will start the process. All plant foods have some lactic acid present.
  • More foods are fermented than you realise – cheese, salami, olives, and other cured meats are all types of fermentation.
  • From a nutritional value stand point, raw dairy is better for fermentation than pasteurized. With pasteurized milk, the fermentation process is activated with a starter culture that has a defined mixture of pure cultures or strains of bacteria, which are nowhere near as diverse as when introduced into already lively bacteria flora found in the raw milk. These live microbes are destroyed during the pasteurization process. However, fermenting pasteurized milk is usually seen as a more stable process as the contributing factors are more constrained and you are more likely to end up with a consistent result. It’s recommended to first ferment some pasteurized milk and then use that as a starter for raw milk.
  • In summer and in warmer locations, expect faster ferments and in winter and cooler locations, where the process will take a little longer. You can use the temperature of the environment to control the speed of fermentation.
  • Adding more salt can slow down the fermentation when it’s warm and will keep it longer in winter.
  • You can use glass, ceramic, plastic and wood containers but not metal. Also beware of using painted ceramic pots as some paints can be lead based, which can leach.
  • Adding tannin rich leaves and foods such as cherry blossom leaves, grape leaves, blossom end of cucumbers and even a tea bag will help to keep vegetables crunchier.
  • Adding caraway, dill and chilies to the ferments can slow down the mold growth.
  • Milk kefir grains have more than 30 different probiotic strains. Kefir is one of the easiest things to make. Kefir grains work best with milk that contains lactose while water kefir grains can be used with non-dairy liquids. Here is an example of how to make a water kefir beverage using water kefir grains and check out this product page and questions and answers about milk kefir grains verses this page about the water kefir grains as they are slightly different things.
  • The most popular fermented foods you can easily find in your local, organic, natural food store or farmer’s market include: raw sauerkraut, kimchi, kombucha, kefir (from cow, goat, or coconut milk), cheeses, pickles, olives, beer, wine, and raw cacao.
  • Sauerkraut is super easy to make at home but if you don’t have the time and you’re planning to buy it ready made, look for the fresh, unpasteurised kind usually kept in the refrigerated section of the store – that’s the kind of sauerkraut with the live bacteria in it.

Take home message!

Fermented foods are foods that have been through a process of lacto- fermentation in which natural bacteria feed on the sugar and starch in the food, creating lactic acid. This process preserves the food, and creates beneficial enzymes and various strains of probiotics, elevates present B vitamins and Omega-3 fatty acids, which help to support our immune function and digestion. Fermented foods are very good for us! BUT you can also have too much good bacteria as I found out later, so introduce fermented foods into your diet slowly and monitor how you feel. Read our other post about the possible side effects of too much fermented food here. 

You can easily ferment many whole foods at home – no special jars and equipment needed – or otherwise most popular ferments can usually be found in your local natural food store or farmer’s market. These include raw sauerkraut, kimchi, kombucha, miso, natto, kefir (from cow, goat, or coconut milk), cheeses, pickles, olives, beer, wine, and even raw cacao.

Make your own sauerkraut with our quick recipe and step by step photos.

References and related reading 

S. Parvez, K.A. Malik, S. Ah Kang3 and H.-Y. Kim, 2005, Probiotics and their fermented food products are beneficial for health, Journal of Applied Microbiology, ISSN 1364-5072

Sally Fallon on Lacto-fermentation http://www.westonaprice.org/health-topics/lacto-fermentation/

Dominique Patton, 04-Nov-2005,  Sauerkraut consumption may fight off breast cancer,  http://www.nutraingredients.com/Research/Sauerkraut-consumption-may-fight-off-breast-cancer

Elizabeth Lipski, 2013, Digestion Connection: The Simple, Natural Plan to Combat Diabetes, Heart Disease, Osteoporosis, Arthritis, Acid Reflux–And More!, Rodale. p. 63. ISBN 978-1609619459.

J T.M Wouters, E H.E Ayad, JHugenholtz, G Smit, Microbes from raw milk for fermented dairy products, International Dairy Journal, Volume 12, Issues 2–3, 2002, Pages 91–109

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